This invention relates to soap bars commonly used for human bathing, but could also be used for a variety of cleansing tasks, such as hand cleaning, animal bathing, garment cleaning, parts cleaning, and other such cleaning. In the hotel industry, it is common to provide a fresh bar of bath soap for each new hotel guest. Some luxury hotel brands also commonly provide a fresh bar of bath soap each day, even for a multi-night stay. The resulting disposal of the bath soap used the prior day creates an undesirable waste stream which must be disposed or recycled.
Bath soap, which is commonly provided as a convenience to hotel patrons, creates unnecessary waste when it is disposed after only one or a few uses. Desirable external dimensions of a bar of soap are large enough to be conveniently held in the user's hand while scrubbing or lathering. Desirable structural properties for a bar of soap are to be strong enough to avoid breakage during the bathing process. Because the lathering and cleansing process involves removal of soap material from only the surface of the bar of soap, the interior solid core soap material is not consumed during a single or few uses, thus becomes a waste when it is no longer desirable to use the soap. This is commonly the practice when hotel patrons bath once or twice in a hotel room shower and then check out of the room and depart. The hotel housekeeping personnel discard or recycle the remaining soap bar as waste, prior to the arrival of the next guest, who expects a fresh bar of soap. This is often done to convey a quality appearance and to promote good personal hygiene.
There are various existing designs of bar soap which minimize resulting waste at the end of useful life. However, many focus on subsequent recycling of soap bar remnants, while others rely on a reusable structural core.
U.S. Pat. No. 4,548,572 to Hoffman describes a device which assists bonding of soap remnants to another bar of soap. This design suffers from the requirement that the remnant be reused by the same bather, or it sacrifices the desired quality appearance and good hygiene. U.S. Pat. No. 6,036,393 to Youtcheff suffers from similar shortcomings. U.S. Pat. No. 4,438,010 to Lindauer incorporates an aromatized plastic core, which may or may not be reusable. This design suffers from the requirement to utilize a material core with significantly different physical composition and properties from the soap covering.
U.S. Pat. No. 7,459,418 to Ozment discloses a design for a method of recharging a structural core. The design describes the process of stripping existing soap from the structural core. This design suffers from the requirement to use a material for the structural core which differs significantly from the soap covering which would facilitate the stripping process without damaging the structural core. U.S. Pat. No. 5,221,506 to Dulin describes a solid soap, and suffers from requiring excess raw materials in manufacturing, and residual material for a solid bar.
U.S. Pat. No. 5,895,780 to Tokosh, et al describes a floating soap which specifies a specific ingredient content. This design suffers from the requirement to incorporate a narrow formulation for the soap material.